Adjustable viscosity sensitive burner control



y 1952 R. B. PLASS 2,597,177

ADJUSTABLE VISCOSITY SENSITIVE BURNER CONTROLS Filed Aug. 30, 1949 &

2 I2 /5 O O F I w IN VEN TOR. A AYMONDB PM ss ATTORNEY Patented May 20, i952 'UNITED S ADJUSTABLE VISCOSITY SENSITIVE BURNER CONTROL Application August 30, 1949, Serial No. 113,172

3 Claims. (01. 137-466) This invention relates to burner controls for oil burners or the like which are sensitive to viscosity in the manner generally described in my Patent No. 2,471,541 of May 31, 1949, entitled Burner Control System Including a Viscosity Sensitive By-Pass Valve.

The use of viscosity controls in an oil burner system is now known and an example of such use is given in the above mentioned patent. The viscosity sensitive valve is employed in a system where a constant volume pump directs oil toward an oil burner and the rate of burning or volume of oil delivered to the burner is controlled by by-passing a given quantity of the constant volume pump output back to the source of supply. In order to avoid variation in flame rate at the burner because of variations in viscosity of the oil as it is being delivered, viscosity controls in the form of Poiseuille tubes are interposed in the burner supply line and in the by-pass line to maintain a constant ratio of flow through these two lines regardless of variations in the viscosity. Two undesirable conditions are encountered in this type of control as previously made, one being that the Poiseuille tubes or viscosity control units have been so arranged that their simple or automatic adjustment to vary flame rate at the burner has been impractical so that an additional by-pass valve in the return line has been provided for this purpose. The other disadvantage is that back pressure in the line leading it to the burner and in the by-pass line effects the viscosity control units and any variation in back pressure that would result from adjustment of the units would tend undesirably to vary the intended ratio of flow.

The present invention is concerned with the correction of the disadvantages mentioned above and has for its object the provision of a viscosity sensitive burner control that is adjustable to vary flame rate at the burner entirely through simple mechanism that alters the positions of the viscosity control members and automatically corrects for any variation in back pressure effecting said. members. Further and more specific objects and advantages of the invention and the mechanism through which it is carried into practice are disclosed in the following specification by reference to the accompanying drawings.

In the drawings:

Fig. 1 is a schematic view of a burner control system embodying the present invention, and

Fig. 2 is an enlarged central longitudinal section through the viscosity control units shown g in Fig. 1 illustrating the manner of their and adjustment.

The burner control system, illustrated schematically in Fig. 1, comprises a burner tip I!) which is disposed in the fire box of a furnace or the like, not shown, and to which oil and air are delivered in a conventional manner to produce a combustible mixture. The rate of flow of oil to the burner tip I0 determines the size of the flame in the fire box and the present invention is concerned with controlling and adjusting this rate, it being desirable to maintain a constant rate of burning for any given setting. The oil consumed at the burner is supplied from a source not shown through a pipe I I being withdrawn therefrom and delivered by a pump 12 to the interior of a reservoir l3. An overflow tube Hi communicates between the reservoir and the source of supply to prevent the building up of excessive pressure in the reservoir. A pump I5, disposed like the pump l2 within the reservoir, is employed for supplying oil to the burner tip I0. A so-called viscosity valve, generally indicated at I6, receives oil from the pump l5 through a pipe line ll and functions to direct a part of the output of the pump I 5 to the burner is and to by-pass the remainder back to the reservoir l3 and thence, if necessary, through the return line Hi to the source of supply. The capacity of the pump I5 is in excess of the maximum requirements of the burner l0 so a portion of the oil flows toward the burner through a tapered port l9 in the viscosity valve controlled by an adjustable tapered plug 20. The remainder of the oil flows through a similar but oppositely directed tapered port 2| with a corresponding adjustable tapered plug 22. These tapered passageways are controlled by their respectiv plugs and form Poiseuille tubes and thus Poiseuilles law becomes effective to maintain a constant ratio between the rate of flow to the burner and rate of flow through the return line regardless of variations in viscosity of the oil. While the theory of viscosity control, herein dis-' closed, has been employed in oil burner systems, the present invention provides a new arrangement of the control units which simplifies their adjustment for maximum firing rate as well as their adjustment for automatic or manual flame control during operation.

As shown in the drawing, the tapered passageways l9 and 2| are axially aligned in end to end relationship as are also the tapered plugs- Zil and 22. The plugs 2i} and 22 are carried on a common supporting assembly generally indicated at 24 support presently to be more specifically described and including a toothed or racked portion 25 adjacent one of its ends. This bar is adjustable axially or lengthwise of the valve housin through means herein illustrated as a gear 26 meshing with the rack 25. The gear 26 is carried on a rotatable shaft 2'} and a lever 28, connected to the shaft and disposed exteriorl of the housing, may be manipulated to move the supporting assembly and plugs 20 and 22 lengthwise 1 with respect to the housing. The gear and rack assembly is of course only typical of many mechanical devices capable of imparting the desired movement to the tapered members or the viscosity valve. As shown in Big. 1,, the delivery pipe I1 is connected with the central portionf the viscosity valve and oil flows outwardly to- Y ward opposite ends of the valve for distribution to the burner tip and the return line. That part of the oil to be directed to the burner tip passes throu h-a oo d t 29 th ugh a pressure balam ing valve, generally indicated at 39, and. then throu h line 3| to the burner tip. Theoil to be returned to the source of supply leaves the viseosity valve by means of a conduit 32, the pressure balancing valve 30 and a return line 33 interposed between the balancing valve and the reservoir I3. A suitable'shut-off valve, usually of the magnetic type, is disposed in the line 3| whieh leads to the burner tip as indicated at 35.

The lever 28 may be manipulated to control the-rate'of firing as open movement to the right, it will move the plugs 28 and 22 to the right with respect to the tapered openings l9 and 2| in which hey e ed. t u du ng the cr section f t e fl ar a t e opening it and at theasa ne me n r as n th oross n of thefio are n h open ng 2L Th r r efi ots ob ain dmov mentof thelever .2 to ard e-lef nd th s le er i i en d e t er or-m nua o er n or fo c n o with a y stii ohleau oma co ol mechanism no s Qr e-oi the advantages'or the present invention results from the arrangement of the tapered plugs 2i) and 22 inthe manner shown topermit of their simultaneous adjustment by simple movement of a single lever. Also the force required iop adjustment is minimized by the balance of the hydraulic thrusts in this assembly.

it is also desirable that the members 28 and 22 he adjustable relative to each other in order to establish a maximum desired firing-rate for the burner and this is accomplished through the up or ing a em ly .24 hich i illustrated i det il i h s 2- The ssemb y 4 c mp a slidable' and rotatable rod 36, shown in Fig. l, as extending through a packing joint 31 at one end of; the housing l6 so that its end projects to a position where it is accessible for rotation by a screw driver or other suitable tool. Pinned to the rod for rotation therewith is a sleeve 38 with a longitudinal slot 39 formed therein. The tap red m mber 22 embraces one e d or this lee e-end ha p tex ndi g n o the s o ss topermit it to slide relative to the rod but to compel it-to rotate with the rod. A second sleeved! is slidably mounted on the rod- 36 and pinned to the tapered member 22 as by a pin 62. This sleeve M has a threaded connection with an axial bore of the tapered member 26 so that upon otatio o th o t. he members it a d 2 wil be ad sted to and-away irom ach o er as desired. Such adjustment of course effects the maximum possible flow through the passage [9 when the lever 28 is swung to'its extreme left position. The rack part 25 is also shown as slidable on the rod 36 and is connected as by a threaded joint with the tapered member 29. This threaded connection may be soldered or otherwise permanently secured after it is made up to prevent a relative rotation of the tapered member 0 nd the ac pa 5- tprefe re t the rack 25and the gear 26 be relatively wide across their respective toothed surfaces and this construction prevents rotation of the rack part when it is assembled and in mesh with the gear. The end 440i the rod 36 may be received in a suitable bore inthe interior of the housing, as shown in Fla-l,

T e pressure balancing valve 30 comprises a cylindrioalhousin as shown, with the oil delivery line 29 and the oil return line 32 connected with'its opposite ends. The housing contains a balanced floating piston assembly including two pistons 46 and 41 slidably mounted in the housins and also slida l o an axially arran ed b .8 A spri 49 is i terposed b tweenthepist ns lifiand 41 and tends normally to urgefithem outwardly oraw y f om a the A entral stop collar Wand end collars 5! are fixed to the bar 48 and limit the travel of the pistons thereon.

In operation, oil pressure in the lines 29 and 32 which communicate with the discharge ends of the two viscosity units urges the pistons 46 and 41 toward each other against the-pressure oi the spring 49 to open communication. with the pipe 3| leading to the burner and with the pipe. 33 communicating with the reservoir l3 and the system functions as heretofore described. If, upon a us ment of the vi cosity ontrol or for ny ther u the pr sure either of the ine 29. o 32 exce ds the p essure in. the other line. th ent rep t n ass mblyin th valve'tt l e urged aw rom the high pressure end of he ylin erand owa d a posit on where the piston on the opposite end closes the discharge por mmunicating with the line 3! or 33. With h p r lo ed or p iallyolos d. th pressure i u ld p until it qualizes that fr m the opposite, side and the piston assembly will, through th s valving tion. some t est at a po nt Where he ui pressure in. i opposite en is equ l. A drain. line 3 pr ferably commun cates b tween the cen ral portion of the valve 30. b twe n the pistons'45 and 4'! and the reservoir l3 so that any oil that. mi h leakp st the pis ons is fr to r turn to a l w pr ssure. area. Be ause the valve 36 maintains equal operating pre sure at the discha e. nds of the Poiseuille. tubes; the volum. ric ratio. of delivery throu h the ubes will remain constant for any setting.

I claim:

1,. A visco ty con r l. sy tem for bur ers or the like which compr e a housing having a pair of axially aligned oppositely disposed tapered fluid passag a taper d contr l p us in ach passage. a upp rtin s emb y or said plugsinol din a member exten ing axially through both passages. rot le m an on s id member with a hreaded connection with one plug to vary the relative positions of the plugs, and slidable means on said assembly to adjust. both plugs with relation to the. passages.

2. A viscosity control system for burners or the like which comprises a housing having a pair of axially aligned oppositely disposed tapered fluid passag s, a taper d ntrol p u a h. p ssa a supporting assembly for said plugs including a, member extending axially through both passages, rotatable means on said member with .a. threaded 5 connection with one plug to vary the relative positions of the plugs, slidable means on said assembly to adjust both plugs with relation to the passages and means operable from the exterior of the housing to actuate said slidable means.

3. A viscosity control system comprising a pair of controlled passages for reception of fluid from a single source, a discharge area for each passage, a pressure balancing valve communicating with the discharge of both passages to maintain equal pressures adjacent the discharge areas or" the passages, said valve comprising a cylinder communicating at each end with one of said passages and having side Wall outlets, a pair of pistons slidable in the cylinder to valve said outlets, and resilient means urging the pistons apart and opposed by pressure in the cylinder ends to urge them together and open said outlets, said pistons and resilient means being slidable as a unit in the cylinder whereby high pressure at one end of the cylinder tends to close the outlet for the other end.

RAYMOND B. PLASS.

REFEBENGES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

